WATERBURY — A man charged as a serial bank robber is trying to have his case transferred out of state court in Waterbury, claiming that for more than a year he has secretly assisted a federal investigation of the man prosecuting him, State's Attorney John Connelly.

The bank robber's assistance — a secretly recorded attempt to engage a Waterbury defense lawyer in a potentially incriminating conversation — produced nothing of value for federal investigators, according to several lawyers involved.

But new information about events connected to the call became public Wednesday and provides another look at the odd relationship between federal authorities, a bank robber and the prosecutor trying to jail him, as well as the persistent federal investigation that has stalked Waterbury's courthouse for more than a year.

One subject of the investigation, according to sources familiar with the matter, is whether Connelly's lifelong friendship with high-profile Waterbury defense lawyer Martin Minnella resulted in improper favors being traded between the two — among the favors, special consideration for Minnella clients by Connelly or members of his staff.

Over several years, Connelly and Minnella, sometimes accompanied by others, occasionally vacationed together or traveled together to sporting events. Connelly has told investigators, according to the lawyers, that he reimbursed Minnella for any expenses Minnella incurred for the travel, usually in cash but at least once by check.

Connelly's lawyer, Hugh Keefe, has said Connelly is a victim of "rumors" and is not the target of any investigation.

"John Connelly is one of the finest prosecutors and public servants in the history of the state of Connecticut," Keefe has said. "He has an unblemished reputation among judges, lawyers and other prosecutors and has had that for over 30 years."

The many accused of bank robbery is 60-year-old Michael Seifert of New Milford. According to police reports, Seifert began robbing banks to pay the bills after his computer business began to fail. He was arrested by Waterbury police two years ago and eventually charged with robbing 13 banks in western Connecticut and New York.

He has been incarcerated since his arrest, awaiting disposition of the charges against him and a potential Connelly-imposed sentence that could run 15 to 20 years.

It was from prison, one of Seifert's public defenders said in an affidavit obtained by The Courant Wednesday, that he "reached out to federal investigators and provided information to them concerning the conduct of Waterbury State's Attorney John Connelly and the manner in which certain decisions by his office may have been compromised."

"Since then, Mr. Seifert has been assisting federal investigators in connection with their investigation, the subject of which is Connelly's conduct as a prosecutor," said the affidavit, signed by attorney Brian Spears.

Spears said in the affidavit, part of more than two dozen pages of secret legal filings made public Wednesday, that he was appointed as Seifert's federal public defender after Seifert contacted federal investigators and volunteered his assistance. Spears could not be reached Wednesday, but said in the affidavit that Seifert had been assisting federal investigators since at least the fall of 2009.

The assistance involved Seifert's placing a telephone call to Minnella — a call that was secretly recorded by federal investigators, according to three lawyers familiar with the events. One of those lawyers, Minnella attorney Norm Pattis, wrote about the call in his personal Internet blog.

Pattis wrote, and the other sources confirmed, that Seifert was recorded asking Minnella to represent him and offering Minnella a fee. Seifert's wife was supposed to deliver the money while wearing a secret government recording device of her own, Pattis wrote.

Pattis said Seifert also was instructed to engage Minnella in a discussion of his relationship with Connelly. But, Pattis wrote, Minnella passed on the offer and the ploy fell apart.

No one involved in the Seifert bank robbery prosecution or the federal investigation would discuss whether his cooperation extended beyond the telephone call. The U.S. attorney's office, which is directing the federal investigation, declined comment, as did Connelly and Chief State's Attorney Kevin Kane.

But one of the sources said that Seifert may have learned of the federal investigation from a fellow inmate. FBI agents have questioned imprisoned Minnella clients about their legal expenses and any promises Minnella may have made about how he would conduct their defenses.

Seifert was scheduled to argue in Waterbury Superior Court Wednesday that his bank robbery case should be removed from Waterbury and from Connelly's control, but the arguments were postponed a week.

Michael L. Moscowitz, who has been appointed as Seifert's state public defender, said he had been prepared to argue that neither Connelly nor his office can be impartial because of Seifert's involvement in the federal investigation.